Pneumatic-dispatch apparatus



Feb. 23 ,1926 1,574,046

7 J. G. MACLAREN PNEUMATIC DI SPATGH APPARATUS Filed Jan. 2 1925 2 Sheets-Sheet 1 Feb. 23 1926.

J. G. M ACLAREN FNEUMATIC DISPATCH APPARATUS 2 Sheets-Sheet 2 Filed Jan. 25, 1925 Patented Feb. 23, 1926.

UNITE STATES aren't orrica.

JAMES G. MACLABEN, OF SYRACUSE, NEW" YORK, ASSIGNOR TO THE LAMSON COM- IPANY, OF SYRACUSE, NEW YORK, A CORPORATION OF MASSACHUSETTS.

PNEUMATIC-DISPATCH APPARATUS.

Application filed January 23, 1925. Serial No. 4,215.

T all whom it may concern:

Be it known that I, Janus G. MACLAREN, a citizen of the United States of America, and resident of Syracuse, in the county of Onondaga and State of New York,have invented new and useful ln'iprovements in Pneumatic-Dispatch Apparatus, of which the following is a specification.

This invention pertains to pneumatic dispatch systems of the closed circuit, vacuum type and relates more particularly to an automatically operating power controller, the principal object of the invention being to provice a device of simple durable and dependable character operative to cut oil the flow of air through the system upon the lapse of a predetermined interval after dispatch of a carrier whereby to avoid the wasteful use of air and needless consumption of power.

In the accompanying drawings a preferred embodiment of the invention is illustrated by way of example,

Fig. 1 being a fragmentary and somewhat diagrammatic front elevation illustrating one complete circuit of a pneumatic dispatch system provided with a power controller embodying the present inven ion,

Fig. 2 is a fragmentary front elevation, to larger scale, of the central station end of the dispatch tube oi the system of Fig. 1 showing the improved power cont-roller ap plied thereto, g

Fig. 3 is a horizontal section on the line 3-3 of Fig. 2,

Fig. 4. is a vertical section on the line 44c of 3, and

Fig. 5 is a fragmentary detail of a valyc device forming an element of the mechanism.

' Referring to Fig. 1 the numeral 1 indicates a table or desk emblematic of the central star tion desk of a pneumatic dispatch system. The power controller 2 forming the specil'ic subject matter of the present invention is interposed between and connects the dispatch terminal or mouthpiece 3 with one end of the dispatch transmission tube 4 leading to a remote sending station indicated diagrammatically at 5. At the station 5 the tube 4 leads into a delivery terminal 6 having an outwardly opening valve 7 through which carriers may emerge, the valve normally being held closed by the external air pressure but opening under impact of a carricr.

The terminal (3 is also provided with an inlet controlled by the normally closed valve 8, such inlet providing for the admission of carriers to the receiving end of the return transmission tube 9 leading to a casing 10 at the central station, said casing having a delivery opening furnished with a normally closed valve 1.1. From the casing 10 an extension 12 of the pipe 9 leads to a vacuum header or drum 13 in which a negative pressure is constantly maintained by means of a pump, blower, or other form of exhauster, not shown.

Referring more particularly to Figs 2 to 5 inclusive the dispatch terminal or mouthpiece 3 is shown as consisting of an open ended cylinder secured by screws to the lower end of the main casing of the power controller 2. This main casing 15 is ot' generally cylindrical form, having a passage 14 aligning with the tube 4- and mouthpiece 3. The main casing 15 is furnished with an offset portion 16 providing a space 17 for the reception of a valve 18 when the latter is swung to open position. The valve 18 is fixedly secured to a shaft 19 journalled in the wall of the casing at the lower part oi the offset 16 and is adapted to engage an inclined seat surface 20 provided by the upper edge of the mouthpiece or terminal 3.

The shaft 19 projects outside the casing and carries an arm 21 furnished with a weight 22 so disposed that it constantly tends to swing the valve away from its seat so as to leave a clear passage through the mouthpiece 3 and casing 15 into the tube The shaft 19 is furnished with a second arm 23 which extends transversely across to the opposite side of the casing shown in Fig. 4.

A cylinder 24: is secured, integrally or otherwise to the side of the casing 15, the cylinder being disposed substantially at the opposite side of the casing from the weight 22 and having a bore parallel to the passage through the main casing. A piston 25 slides in the bore in cylinder 2% and is furnished with a piston rod 26 whose lower end is adapted to contact at times with a lateral flange 27 on the free end of lever arm 23 thereby holding valve 18 closed in opposition to the weight 22.

Just above the offset portion 16 of the main casing the latter is provided with a circular depression 28 having a rim 29 to which the edge or" a flexible diaphragm 30 is secured by means of a concave cover plate 31. The chamber formed by the depression 28 and diaphragm 30 is connected through port 32 and pipe 33 withthe dis patch tube 4 at a point so remote from the terminal 3 that pressure conditions will not be greatly affected by the opening of the valve 18. The space between the diaphragm 30 and the cover 31 is at all times freely open to the atmosphere through ports 34.

The cover 31 is provided with a concentric hollow sleeve or valve cylinder 35 projecting from its outer surface. The body of this valve cylinder is furnished with two spaced enlargements or chambers 36 and 37 respectively. The chamber 36 communicates by means of a pipe 38 with the upper end of cylinder 24, while the chamber 37 is connected by a pipe 39 to a source of low pressure, for example, as shown in Fig. 1, to the tube 12.

The outer end of the valve cylinder 35 is closed by means of a cap 40 provided with a chamber 41 communicating by means of a pipe 42 with the lower end of cylinder 24; The outer end of the cap 40 is provided with a centrally disposed opening for guiding the rod or stem of a reciprocating valve 43 (Figs. 4v and 5). The valve rod comprises two coaxial sections 44 and 45 respectively, the section 44 having an axial pin at its inner end telescopically engaging an axialjbore in one end of the section 45. The opposite end of the section 45 is fixedly se, cured'to the center of the diaphragm 30. A coil spring- 46 surrounds section 44 of the stem, tending to-push the valve 43 to the left as viewed in Fig. 4, while a heavier spring 47 surrounding the valve stem section 45 tends to move the valve to the right.

When in its extreme left hand position as shown in Fig. 4, the valve closes a'passage 48 leading from chamber 37 to chamber 36, but when moved in the opposite direction it opens said passage and closes a passage 49 leading from chamber 37 to chamber 41.

The outer end of the cap 40 is furnished with one or more openings 50 for admitting air at atmospheric pressure to chamber 41. The openings 50 are controlled by a valve disc 51 secured to valve stem section 44 at a point outside the cap. The disc 51 closes the openings 50 whenever the valve 43 closes passage 48.

The outer end of stem member 44 is furnished with an elongate seat or recess 52 for the reception of one arm of a bell crank lever 53 whose other arm is connected to one end of a: link 54. The other end of the link 54 is pivotally connected to the-outer end of an actuator lever 55 pivoted upon a shaft 1 and 4, all of the valves leading to the.

ransmission tubes being closed and a vacuum or negative pressure existing in the entire system.

When a carrier is pushed up into mouthpiece 3 of the dispatch terminal of the central station it swings trip arm 57 in a clockwise direction, pulling down on link 54' and moving the stem of valves 43 and'50 to the right, thereby opening passages 48 and 50 and closing passage 49. The low pressure valve chamber 37 now communicates through passage 48, chamber 36 and pipe 38 with. the upper part of the cylinder 24 while atmospheric air is free to enter the lower end of cylinder 24 through openings 50, chamber 41, and pipe 42. The air pressure acting on the underside of piston 25 quickly raises the latter and removes the end of piston rod 26 from the flange 27 whereupon weight 22 opens valve 18,the entire sequence of operations just described taking place almost instantaneously.

The carrier now enters the passage through casing 15 and is driven toward the terminal 6 by atmospheric pressure, valve 18 being held open meantime by weight 22.

As soon as the carrier passes trip arm 57 the latter is returned to its normal position by the spring 59, thereby resetting valves 43 and 50. In the restored position of valves 43 and 50 the low pressure valve chamber. 37 is cut off from the upper end of cylinder 24 but now communicates through passage 49, chamber 41 and pipe 42 with the lower end of said cylinder. As the chamber 36 is now sealed no air can enter the upper end of cylinder 24 except as it is permitted slowly to bleed in through an adjustable needle valve 60. As the air slowly enters the upper end of cylinder 24 the piston 25 gradually descends until at about the time the carrier emerges-at delivery terminal 6 the piston rod 26 engages the arm 27, and closes the valve 18. The interval elapsing between the opening and closing of valve 18 depends upon the setting of valve 60 and may be varied in accordance with the length of the transmission tube and other controlling factors.

When the carrier is inserted in the. terminal 6 for return to the central station the .opening of valve 8 produces a sudden rise chamber 28 thus permitting the relatively heavy spring 47 to force the 'valve stem sections and 44: to the right 4) shifting the valves 43 and to the right and thereby initiating the sequence of operations above described which results in opening valve 18 so that atmospheric air entering the mouthpiece 3 passes through tube 4 and terminal 6 and pushes the carrier along tube 9 to the terminal 10.

As soon as the carrier fully enters tube 9 it chokes 0d the free entrance of air at Cal terminal 8 so that the vacuum is again established in pipe 9 and acting upon diaphragm 30 moves the valve stem to the left, restoring valves 43 and 50 to normal position. I

The timing valve 60 now operates just as above described to close valve 18 after the desired interval.

Vllhat I claim is:

1. Power controlling apparatus for a pneumatic dispatch system of the vacuum, closed tube type, comprising a dispatch terminal provided with a valve controlling the entry of atmospheric air, means tending to open the valve, retaining means normally locking the valve in closed position, and means actuable by a carrier thrust into said terminal temporarily to render the retaining means inoperative whereby to permit the valve quickly to open and thereafter slowly to return the valve to closed position.

2. In pneumatic dispatch apparatus, a tube terminal device including a normally closed inlet valve biased to move to open position, means for retaining the valve in closed position, and means for releasing the retaining means to permit the valve to move to open position, said retaining means returning the valve to closed position a predetermined time after the valve has opened.

3. In pneumatic dispatch apparatus, a tube terminal device including a normally closed inlet valve biased by g 'avity to move to open position, pneumatic means for retaining the valve in closed position, and means for causing the pneumatic means to release the valve and permit it to move to open position, said pneumatic means restoring the valve to closed position after it has opened. p I

4:. In pneumatic dispatch apparatus, a tube terminal device including a normally closed inlet valve biased to move to open position, pneumatic means for retaining the valve in closed position, and means for causing the pneumatic means to release the valve and permit it to move to open position, said pneumatic means restoring the inlet valve to closed position a predetermined period of time after it has opened.

5. Power controlling apparatus for a pneumatic dispatch system of the vacuum,

closed tube type comprising an inlet valve, means tending to open the inlet valve, rctaining means normally holding the valve closed, said retaining means comprising a pressure responsive device norn ally exposed on its lower side to low pressure, shifting means actuable by a carrier to shift the low pressure conditions to the upper side of the pressure responsive device whereby to release the inlet valve, said shitting means being restored to initial position upon opening of the inlet valve, and means permitting atmospheric pressure to build up slowly upon the upper side of the pneumatic after restoration of the shifting means to normal position whereby the pneumatic is permitted slowly to return to normal position.

(3.1m pneumatic dispatch apparatus, a tube terminal device including a normally closed inlet valve biased to move to open position, pneumatic means for retaining the valve in closed position, means including an auxiliary valve adapted to be operated by the insertion of a carrier in the terminal device to cause the pneumatic means to release the inlet valve and permit it to move to open position, and spring means operative to restore the auxiliary valve to normal position whereby to permit the pneumatic means to close the inlet valve.

7.1n pneumatic dispatch apparatus, a tube terminal device including a normally closed inlet valve biased to move to open position, means normally retaining the valve in closed position, controlling means including a pneumatically actuable auxiliary valve acting, upon the occurrence Of a predetermined pressure condition in a dis iatch tube, to cause the retaining means to release the inlet valv and permit it to open, said auxiliary valve thereafter acting to cause the pneumatic means to restore the inlet valve to closed position.

8. In pneumatic dispatch apparatus, a tube terminal device including a normally closed inlet valve biased to move to open position, pneumatic means normally retaining the valve in closed position, controlling means including an auxiliary valve and a trip member, the trip member being actuable by a carrier inserted in the terminal de vice to shift the auxiliary valve thereby causing the pneumatic means to release the inlet valve and permit it 'to open, and spring means operative to restore the auxiliary valve to normal position when the carrier moves out of engagement with the trip member thereby to cause the inlet valve retaining means to return to normal position after a predetermined period of time.

9. In pneumatic dispatch apparatus, a tube terminal device including a normally closed inlet valve biased to move to open posit-ion, pneumatic means normally retaining the valve in closed position, controlling means including an auxiliary valve, and pressure responsive means for moving said auxiliary valve, said pressure responsive means being subject to pressure conditions in a dispatch tube and acting so to set the auxiliary valve upon the occurrence of .a predetermined pressure in the tube as to cause the retaining means to release the inlet valve and permit it to open, and means for returning the auxiliary valve to normal position thereby causing the pneumatic means to close the inlet valve a predeterminedperiod of time after it has opened.

10. In a pneumatic dispatch apparatus, an oi'itgoin'g dispatch tube, a return dispatch tube, an exhaust source connected with the delivery end of said return tube, a normally closed inlet valve for the inlet end of said outgoing tube, said valve tending to move to open position, pneumatic means for retaining the valve in closed position, and auxiliary valve mechanism operated by the insertion of a carrier in either tube to cause the pneumatic means to release the valve and permit it to move to open position.

'11. In a pneumatic dispatch apparatus, an outgoing dispatch tube, a return dispatch tube, an exhaust sourceconnected with the discharge end of said return tube, a normally closed inlet valve for the inlet end of said outgoing tube, said valve tending to move to open position, pneumatic means for retaining the valve in closed position, an auxiliary valve for controlling the operation of said pneumatic means, a trip engageable by the insertion of a carrier in said outgoing dispatch tube for moving said auxiliary valve from its normal position, and means subject to pressure conditions Within said return tube also operable to move the auxiliary valve from its normal position, whereby the insertion of a carrier in either tube will actuate the auxiliary valve to cause the pneumatic means to release the inlet valve and permit it to move to open position,

12. In a pneumatic dispatch apparatus, an outgoing dispatch tube, a returndispatch tube, an exhaust source connected With the dischargeend of said return tube, a normally closed inlet valve for the inlet end of said outgoing tube, said valve tending to move to open position, pneumatic means for retaining the valve in closed position, an auxiliary valve for controlling the operation of said pneumatic means, a trip actuable by a carrier inserted in said outgoing dispatch tube for moving said auxiliary valve and a pneumatic subject to pressure conditions in one of said tubes and operable independently of thetrip for moving the auxiliary valve, whereby the insertion of a carrier in either tube will operate the auxiliary valve and cause the retaining means to release the inlet valve and permit it to move to open position, said retaining means operating to close the valve a predetermined period of time after it has opened.

13. A power controller for a pneumatic dispatch system of the closed transmission tube, vacuum type having a dispatch tube communicating with an exhauster, said controller comprising a casing disposed at the dispatch end of the dispatch tube, said casing being provided with a main valve to control the entry of air to the tube, means tending to open the main valve, retaining means for holding the main valve shut CO1 prising a cylinder closed at its ends, a piston sliding in the cylinder, said piston having a rod adapted to engage a part connected to the valve, an auxiliary valve normally positioned to admit low pressure to act on the lower side of the piston to hold its rod in main-valve closing position, a trip lever actuable by a carrier inserted in the dispatch end of the dispatch tube for shifting the auxiliary valve to admit low pressure to act on the upper side of the piston and atmospheric pressure upon the lower side of the piston whereby tomove the latter and release the main'valve, a pneumatic oper- JAMES e; MACLAREN. 

